• Title/Summary/Keyword: coupling model

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FE Analysis of Rock-Socketed Drilled Shafts Using Load Transfer Method (유한요소해석을 통한 암반에 근입된 현장타설말뚝의 하중전이거동 분석)

  • Seol, Hoon-Il;Jeong, Sang-Seom;Kim, Young-Ho
    • Journal of the Korean Geotechnical Society
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    • v.24 no.12
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    • pp.33-40
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    • 2008
  • The load distribution and deformation of rock-socketed drilled shafts subjected to axial loads are evaluated by a load-transfer method. The emphasis is on quantifying the effect of coupled soil resistance in rock-socketed drilled shafts using the 2D elasto-plastic finite element analysis. Slippage and shear load transfer behavior at the pile-soil interface are investigated by using a user-subroutine interface model (FRlC). It is shown that the coupled soil resistance provides the influence of pile toe settlement as the shaft resistance is increased to an ultimate limit state. The results show that the coupling effect is closely related to the value of pile diameter over rock mass modulus (D/$E_{mass}$) and the ratio of total shaft resistance against total applied load ($R_s$/Q). Through comparisons with field case studies, the 2D numerical analysis reseanably presented load transfer of pile and coupling effect due to the transfer of shaft shear loading, and thus represents a significant improvement in the prediction of load deflections of drilled shafts.

Autopilot design for BTT flight vehicles (이동중인 비행시스템의 자동조종장치 설계)

  • 백운보;허남수;이만형;황창선
    • 제어로봇시스템학회:학술대회논문집
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    • 1989.10a
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    • pp.87-92
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    • 1989
  • An autopilot for the class of Bank-To-Turn missiles is developed using a multivariable plant model & control design methodology. The roll-pitch-yaw cross coupling is included in the design considerations. Feedback system is designed using the Linear Quadratic Gaussian with Loop Transfer Recovery (LQG/LTR). Nonlinear simulations are presented to demonstrate the performances of the designed system.

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Dispersion Modeling of Fine Carbon Fibers in Atmospheric Boundary Layer (대기경계층에서 미세 섬유 확산 모델링)

  • Kim, Seog-Cheol;Hwang, Jun-Sik;Lee, Sang-Kil
    • Journal of the Korea Institute of Military Science and Technology
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    • v.11 no.3
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    • pp.169-175
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    • 2008
  • A fine carbon fibers dispersion model is implemented to calculate the scattering range and ground level concentration of carbon fibers emitted at certain altitudes of atmospheric boundary layer. This carbon fibers dispersion model was composed by coupling a commonly used atmospheric dispersion model and an atmospheric boundary layer model. The atmospheric boundary layer model, applying the Monin-Obukov Similarity Rule obtained from measurement input data at ground level, was used to create the atmospheric boundary layer structure. In the atmospheric dispersion model, the Lagrangian Particle Model and the Markov Process were applied to calculate the trajectory of scattered carbon fibers relative to gravity and aerodynamic force, as well as carbon fibers specification.

Conversion of Extraordinary Waves into Upper Hybrid Waves in Inhomogeneous Plasmas

  • Kim, Gyeong-Seop;Kim, Eun-Hwa;Lee, Dong-Hun
    • Bulletin of the Korean Space Science Society
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    • 2004.04a
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    • pp.35-35
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    • 2004
  • Inhomogeneity Is important in wave coupling and mode conversion. We numerically examine the conversion of extraordinary(X) waves into upper hybrid(UH) waves in inhomogeneous plasmas by using a three-dimensional multi-fluid numerical model. A one-dimensional Inhomogeneous density profile is assumed in a cold and collisionless plasma. The density gradient is taken to be perpendicular to the magnetic field. An impulsive input is assumed to excite the X waves in the inhomogeneous box model. (omitted)

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Coupled autopilot design for STT missiles (STT 방식의 유도탄에 대한 결합 자동조종장치 설계)

  • 송찬호;김윤식
    • 제어로봇시스템학회:학술대회논문집
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    • 1992.10a
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    • pp.412-417
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    • 1992
  • In this paper, we present a method to design a coupled autopilot for STT missiles which have severe aerodynamic cross-coupling. The aerodynamic model is derived in the meneuver plane and, based on that model, an autopilot scheduled by the normal acceleration and the estimated bank angle is designed. Bank angle is obtained by a simple estimator. With the proposed autopilot, it is shown by computer simulations that induced moments are properly compensated and the performance is supiorior to the conventional autopilot.

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Time-Domain Numerical Investigation of Ring Resonator Optical Delay Devices

  • Chung, Youngchul
    • Journal of the Optical Society of Korea
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    • v.17 no.5
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    • pp.441-446
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    • 2013
  • A split-step time-domain model for the analysis of pulse delay characteristics through ring resonator all-pass filters (APF's) is developed and its accuracy is checked. The dependence of the delay time and pulse distortion on the coupling ratios is investigated using the model. It is observed that the bandwidth of the APF's needs to be wide enough to minimize the pulse distortion.

A numerical study on the coupled thermo-hydro-mechanical behavior of discontinuous rock mass (불연속암반에서의 열-수리-역학적 상호작용에 대한 수치해석적 연구)

  • 김명환;이희석;이희근
    • Tunnel and Underground Space
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    • v.9 no.1
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    • pp.1-11
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    • 1999
  • A finite element code was developed to analyze coupled thermo-hydro-mechanical phenomena. This code is based on the finite element formulation provided by Noorishad et al. (1984) and Joint behavior was simulated Goodman's joint constitutive model. The developed code was applied for T-H-M coupling analysis for two kinds of shaft models, with a joint or without a joint respectively. For a model without a joint, temperature increased from the shaft wall to outward evidently. The radial displacement showed opposite directions of outward and inward at some distance from shaft wall. For a model with a joint, closure of joint was found due to thermal expansion. The temperature distribution along a joint showed relatively lower than that of rock matrix because of low thermal conductivity and high specific heat of water. And it could be concluded that effects of thermal flow to joint were more than that of hydraulic flow in a rock mass.

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AJFCode: An Approach for Full Aspect-Oriented Code Generation from Reusable Aspect Models

  • Mehmood, Abid;Jawawi, Dayang N.A.
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.16 no.6
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    • pp.1973-1993
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    • 2022
  • Model-driven engineering (MDE) and aspect-oriented software development (AOSD) contribute to the common goal of development of high-quality code in reduced time. To complement each approach with the benefits of the other, various methods of integration of the two approaches were proposed in the past. Aspect-oriented code generation, which targets obtaining aspect-oriented code directly from aspect models, offers some unique advantages over the other integration approaches. However, the existing aspect-oriented code generation approaches do not comprehensively address all aspects of a model-driven code generation system, such as a textual representation of graphical models, conceptual mapping, and incorporation of behavioral diagrams. These problems limit the worth of generated code, especially in practical use. Here, we propose AJFCode, an approach for aspect-oriented model-driven code generation, which comprehensively addresses the various aspects including the graphical models and their text-based representation, mapping between visual model elements and code, and the behavioral code generation. Experiments are conducted to compare the maintainability and reusability characteristics of the aspect-oriented code generated using the AJFCode with the most comprehensive object-oriented code generation approach. AJFCode performs well in terms of all metrics related to maintainability and reusability of code. However, the most significant improvement is noticed in the separation of concerns, coupling, and cohesion. For instance, AJFCode yields significant improvement in concern diffusion over operations (19 vs 51), coupling between components (0 vs 6), and lack of cohesion in operations (5 vs 9) for one of the experimented concerns.

Mathematical Model for Power Transmission - Vehicle System Coupling Analysis (동력전달계와 차량계의 연성 해석을 위한 수학적 모델의 개발)

  • Kong, Jin-Hyung;Park, Jin-Ho;Jo, Han-Sang;Park, Yeong-Il;Lee, Jang-Moo
    • Proceedings of the KSME Conference
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    • 2000.04a
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    • pp.696-701
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    • 2000
  • In this study, a mathematical model fur analyzing the shift characteristics is proposed. The proposed model comprises power transmission system and vehicle system, which are coupled. And On-road car test is carried out in order to extract model parameters. Tile model is composed of a detailed powertrain, an engine/AT housing, a simplified suspension system. tires and a vehicle body model. On the test, the vehicle accelerations and pitch ratio are measured by using accelerometers and gyro sensor. The other data, for example speeds, a throttle position and a brake signal, are taken from sensors which already exist in the vehicle. Using natural frequency and characteristic equation, vehicle model parameters are extracted from experimental data.

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Seismic damage vulnerability of empirical composite material structure of adobe and timber

  • Si-Qi Li
    • Earthquakes and Structures
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    • v.25 no.6
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    • pp.429-442
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    • 2023
  • To study the seismic vulnerability of the composite material structure of adobe and timber, we collected and statistically analysed empirical observation samples of 542,214,937 m2 and 467,177 buildings that were significantly impacted during the 179 earthquakes that occurred in mainland China from 1976 to 2010. In multi-intensity regions, combined with numerical analysis and a probability model, a non-linear continuous regression model of the vulnerability, considering the empirical seismic damage area (number of buildings) and the ratio of seismic damage, was established. Moreover, a probability matrix model of the empirical seismic damage mean value was provided. Considering the coupling effect of the annual and seismic fortification factors, an empirical seismic vulnerability curve model was constructed in the multiple-intensity regions. A probability matrix model of the mean vulnerability index (MVI) was proposed, and was validated through the above-mentioned reconnaissance sample data. A matrix model of the MVI of the regions (19 provinces in mainland China) based on the parameter (MVI) was established.